Question that broke Milat’s brother Boris

The older brother of Ivan Milat has broken down in tears on camera hours after his serial killer brother died from cancer.

Boris is one of the only members of the Milat family to denounce his brother and was always the loudest in his criticism against Australia's worst serial killer.

The 77-year-old also raised his first wife Marilyn's daughter Lynise - even after finding out the child was not his but Ivan's. Lynise was the result of a lengthy affair between Ivan and Marilyn.

Sitting down with 60 Minutes on Sunday, Boris shook as he described Ivan as "an evil serial killer".

"I see a frail old pathetic man that to me he died a long time ago he's nothing but an evil killer," Boris said, after watching a video of Ivan being wheeled from Prince of Wales Hospital in Sydney's east.

Ivan spent months in and out of the hospital, receiving chemotherapy treatment there, before his death at Long Bay Jail early this morning.

"Don't forget this man has proved to kill seven backpackers in a murderous way tore at them like animals tortured their bodies even after they were dead. This man is just an evil serial killer right to the last bone of him - he was dead to me a long time ago," Boris said.

Boris and Ivan were two of 14 children born to parents Steven and Margaret Milat. The rest of Ivan's siblings still defend him to this day, refusing to believe he could be guilty of killing seven backpackers in the 1980s and 1990s.

"I'm a voice in the wilderness," Boris said, describing how his family still denies Ivan's crimes.

"Yelling out to them. And they think I'm just being vicious towards Ivan. And the thing is, I just want the truth out there. They're denying that he did anything. They're denying that he killed anybody. They are saying that the police made it all up.

"I'm putting it out there on the family now, and I can't push it enough, these mongrels hate my guts because I'm the one guy that speaks out.

"But somebody's got to tell these mums and dads why their kids died, why this mongrel thinks he can wipe them out like a dirty rag."

Boris denounced his dead killer brother. Picture: 60 Minutes

Speaking to the current affairs program, Boris said he was "embarrassed to be a Milat" but it was one question from journalist Tara Brown that hit home for the serial killer's brother, leading to him walking out of the interview and coming back in tears.

"When you learned about how those backpackers were killed and toyed with, played with, brutally murdered," Brown started.

"Oh, don't even talk to me about it. Don't want to go there, I'll get emotional," Boris cut in before walking away from the camera.

Boris Milat overcome with emotion. Picture: 60 Minutes

"What can I say, you're just pulling on my heartstrings there a bit," he continued after returning to his seat.

"I'm a bit surprised by your reaction," Brown admitted.

"I don't want to go into that part of it, okay? Because that upsets me," Boris replied.

"People have got a right to die properly, in an accident or whatever, you don't need some mongrel to come and do those things...It's okay, move on. That's good and done. Please."

Terminally ill Milat had been under heavy guard in the intensive care unit of Prince of Wales Hospital but was returned to jail on Tuesday after it became clear death was imminent.

NSW Counter Terrorism and Corrections Minister Anthony Roberts told The Daily Telegraph Milat had shown no remorse for his crimes and deserved no mercy on his deathbed, adding he could "rot in hell".

"He was sentenced to die in jail and he was going to die in jail," Mr Roberts said.

"I wasn't going to have him take up a public hospital bed. Both the commissioner and I were of that opinion.

"We had him removed from a hospital and sent back to Long Bay Jail. He can rot in hell.

"He showed no remorse. We ensured the sentence was carried out."

Milat had been in prison since his 1994 arrest for the murders of seven backpackers whose remains were found in the Belanglo State Forest, an hour's drive north of Goulburn.

He was convicted in 1996 and given seven consecutive life sentences but detectives always feared his murder tally was much higher, with up to six more victims whose bodies have never been found.

Despite pleas from police and families of his suspected victims, Milat took his secrets to the grave.

A Corrective Services spokesperson told news.com.au the serial killer was "found dead in his cell" just after 4am.

Milat was diagnosed with oesophagus and stomach cancer and given three months to live back in May, taking a turn for the worse on October 14.